Digital PWM controller with feed-forward compensation

This paper describes a complete digital PWM controller IC with feed-forward compensation of the input voltage. The feed-forward compensation is accomplished through a delay-line digital pulse-width modulator (DPWM) where the cell delay is made inversely proportional to the input voltage. The complete digital controller IC with the feed-forward DPWM operating at 1 MHz switching frequency can be used in a range of DC-DC applications. In particular, with low power consumption, small silicon area (less than 0.25 mm/sup 2/ in a standard 0.5 /spl mu/ CMOS process) and a programmable compensator requiring no external passive components, the controller is targeted to DC-DC conversion applications in low-power battery-operated electronics. Experimental results are presented for the feedforward DPWM and mixed signal simulations show the validity of the complete digital PWM controller chip.